Steam-engine.



No. 774,434. PATENTED NOV. 8, 1904. D. E. JOHNSON.

STEAM ENGINE.

APPLICATION FILED NOV. 27, 1903.

N0 MODEL.

- No. 774,434. PATENTED NOV. 8, 1904.

D..E. JOHNSON.

STEAM ENGINE.

APPLICATION FILED NOV. 27, 1903.

N0 MODEL. 3 SHEETS-SHEET 2.

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No: 774,434. PATENTED NOV. 8, 1904. D. E. JOHNSON.

STEAM ENGINE.

APPLICATION FILED NOV. 27, 1903.

no MODEL. SSHBETS-SHEET s.

TED STATES PATENT Patented November 8, 1904.

FFIQEo DANIEL E. JOHNSON, OF HARTFORD, CONNECTICUT, ASSIGNOR TO FREDERIC C. BILLINGS, OF HARTFORD, CONNECTICUT.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 774,434, dated November 8, 1904.

Original application filed August 4, 1902, Serial No. 118,256. Divided and this application filed November 27, 1903. Serial No. 182,755. (No model.)

with engine valve-gears, the present application being a divisional of my copending application, Serial No. 118,256, filed August A, 1902.

My invention will be best understood from the following description, taken in connection with the accompanying illustrations, which show one specific embodiment of my invention submitted for illustrative purposes, while its scope will be more particularly pointed out in the appended claims.

In the drawings, Figure l is aside elevation, partially in section and partially broken away,

showing one embodiment of my invention as applied to a type of engine here selected for the illustration thereof. vation, partially broken away and partiallyin section, showing the connection between the eccentrics and the valves. Fig. 3 is an enlarged detail looking down upon the reversing mechanism of the invention illustrated. Fig. 4 is a vertical longitudinal section on the dotted line A A of the parts shown in Fig. 3. Fig. 5 is a view similar to Fig. 4, showing the parts in reversing position. Fig. 6 is a diagram illustrating the relative locations of the two eccentrics, showing the lost motion between the same.

I have herein shown one form or embodi ment of my invention for illustrative purposes applied to an engine of the type shown in the drawings, which is herein provided with four cylinders, two high-pressure a a and two low-pressure b d, shown as formed within a single casting A, mounted upon and secured to the hollow two-part well-like bot- Fig. 2 is an end eletom casting C. The several cylinders are arranged in alinement with the crank-shaft, the two high-pressure cylinders being together and the two low-pressure cylinders together. The two-part bottom or well casting C is divided horizontally, preferably in the plane of the crank-shaft, its two parts being suitably connected, as by bolts cc, Fig. 1, they having formed between them the bearings 0' for the crank-shaft D. The crank-shaft is provided with four cranks arranged in pairs, the cranks of each pair being arranged opposite each other-that is, one hundred and eighty degrees apartthe cranks of the two being arranged on the qnarter-that is, ninety degrees apart.

Referring to Fig. 1, the two cranks for the high-pressure cylinders a a are actuated by the connecting rods or pitmen a a, connected at their upper ends to the hollow wristpins a carried in and by the cup-shaped single-acting high-pressure pistons (63. These pistons are of sufficient length, together With the length of the cylinders, to serve as guides for the pistons in their movements, as is commen with single-acting engines. The two cranks; for the low-pressure cylinders are similarly actuated by the connecting rods or pitmen d 5', connected at their upper ends to the wrist-pins 6 carried in and by the lowpressure pistons 6 Thus the two high-pressure pistons and their cranks balance each other, and also the two low-pressure pistons and cranks.

The upper ends of the several cylinders are closed by a cap-casting E, secured to the cylinder-casting A and containing the several inlet and exhaust ports and valves.

The engine herein shown isprovided with ahigh-pressure valve and a low-pressure valve, provided, respectively, with valve-stems e and f, threaded at their outer ends each to receive two nuts e e and f"f, adapted to retain between them the upper ends of the high and low pressure actuating-arms e and f respectively. The high-pressure actuating-arm e is secured to the tubular rock-shaft 6 and the low-pressure actuating-arm f is secured to the rock-shaft f concentric with the tubular shaft a and actuated therewith by mechanism to be described.

A suitable throttle F controls the admission of steam from a steam-inlet pipe G to the engine, and there is also provided a controllingvalve having a valve-stem H under the control of the operator, in one position of which live steam is admitted directly and independently to both the high and low pressure valve chambers and exhausted independently to the exhaust-pipe 1, whereby the cylinders can be operated singly and the engine run as a simple engine, as when starting or when working under heavy loads. 1n the other position of the controlling-valve the live steam is admitted first to the high-pressure cylinders, the exhaust from both of which afterward passes to a receiver, and thence to the lowpressure-valve chamber, passing to the exhaust-pipe I only after its emergence from the low-pressure cylinders, the engine under such conditions obviously being run on the compound system. The mode of operation and the details of the valves are more particularly set forth in my aforesaid copending application Serial No. 118,256, to which reference may be had.

Having referred to the valve movements, 1 will now describe the valve-actuating mechanism.

Referring to Figs. 1, 3, and 4, the crankshaft 1) has a reduced end portion (Z, upon which is arranged a sleeve (Z, to which is keyed the eccentric (Z for actuating the low-pressure valve. Said eccentric is embraced by a suitable eccentric-strap (Z Figs. 1 and 2, the rod (Z of which is jointed to an arm (Z fast on the end of the low-pressure-valve rockshaftf". Loosely surrounding the sleeve Cl is a second eccentric (l connected with and E to operate the high-pressure valve, said eccentric having its strap cZhFig. 1, provided with an eccentric-rod (Z jointed at its upper end to an arm (Z fast on the end of the tubular high-pressure rock-shaft 0. Thus rotation of the sleeve carrying the said eccentrics will cause the said valve-actuating rockshafts f and e to be rocked, thereby to reciprocate the valves, as described. The sleeve cl is arranged to have partial rotation about and upon the reduced end of the crank-shaft, said sleeve being provided with end-thrust ball-bearings 0 between its ends and the collars 0, fast on the said shaft. The end of the crank-shaft is made tubular, as at to receiving a sliding plug 0 on the end of a stem 0 which extends outward and has mounted upon its end a yoke O. Surrounding the stem 0 of the plug 0 is a bushing 0", secured by a nut 0 screwed upon the end of the stem. is threaded at 0, and the yoke O is screwed The outer end of the said bushing which projects radially through a straight longitudinal slot (I in the end of the crank shaft D and enters a spiral slot (Z in the partially-rotatable sleeve d. Preferably the said stud 0 will have rollers 0" 0 to engage, respectively, the walls of the said slots. Thus with the crank-shaft in a given rotative position if the yoke 0 be moved to draw the plug 0 outward the straight slot (Z in the said shaft will enforce perfectly straight longitudinal and non-rotative movement of the said stud, and this non-rotative movement of the stud acting in the spiral slot (Z of the sleeve (Z will cause partial rotation of the said sleeve through a distance determined by the pitch of the slot and which is suflicient to reverse the positions of the valves and reverse the engine. As the sleeve rotates it carries with it the two eccentrics (Z and (Z shifting the latter on and relative to the crank shaft through a sufficient distance to shift the valves and reverse the engine, it being well understood by those conversant with the art that if a steam-engine be stopped after having run in one direction and its eccentrics be rotated in the proper direction through approximately ninety degrees to one hundred degrees the engine when again started will run in an opposite direction.

The point of cut-off for the low-pressure valve for the best results should be later than that of the high-pressure valve. Consequently in reversing the low-pressure valve from a given point of cut-ofl' in one direction to a corresponding cut-off in a reverse direction the low-pressure eccentric is required to move through a greater distance than the high-pressure eccentric. I have found with the engine here shown that for the best results the lowpressure eccentric should be shifted through approximately one hundred and four degrees, while the high-pressure eccentric should be shifted through not more than ninety-three degrees, and since both eccentrics are shifted by one and the same sleeve d, which of course must move a suflicient distance to shift the eccentric requiring the greatest movement, it becomes necessary to provide a lost motion between such sleeve and the low-pressure eccentric having the least shifting movement.

This I have accomplished by mounting the high-pressu re eccentric loosely upon the sleeve (6, as described, instead of keying it thereto, as is the low-pressure eccentric. The highpressure eccentric is further provided with a laterally-extended stud (Z (see Figs. L and 6,) which stud is extended through a slot (Z in the low-pressure eccentric (2 When now the eccentrics are to be shifted for reversing, the

E sleeve (Z and low-pressure eccentric (Z will move for a distance, approximately eleven degrees, before the end of its wall 6 w1ll meet the stud t after which, acting through said thereupon and against the shoulder 0 thereof. stud, the two eccentrics will move in unison. This axially-movable plug 0 has a stud 0 l Conversely, uponreturnmovement of the lowtrance terminatingin a sharp edge (P the other end wall of said slot will meet the said stud and carry with it the high-pressure eccentric.

The shifting movement of the high-pressure eccentric (Z is limited in both directions by a stop 6 Fig. 3, on the collar 0', which stop is accurately positioned to permit the said eccentric to shift through the required distance for reversing its valve. Consequently when shifted in either direction against this stop the said eccentric is held tightly clamped or positioned between said stop, on the one hand, and the end wall of the slot in the low-pressure eccentric acting upon the stud (Z on the other hand,

thus guarding against any possible looseness,

the lowpressure eccentric itself being held firmly in either of its positions by the cooperating slots (Z and (Z The yoke 0 (see Fig. 3) has its arms provided with studs 0 which are engaged by the clepending arms 0 (see Figs. 1 and 2) on the reversing-shaft 0 The eccentrics, rods, and connections likewise are arranged in a housing S, the only protruding part being the end of the bushing 0*, which surrounds the plug-stem 0 and which has no rotative movement whatsoever, but merely out-and -in movement, requiring little lubrication and admitting little or no dirt. Since the principal movements of the engine will be in a forward direction, I have so arranged the parts that the plug occupies an inward position to produce forward motion of the engine and have provided a packingwasher 0 at the inner side of the bushingflange 0 which during forward motion of the engine is brought close against the protectinghousing S further to guard against possible entrance of dirt to the interior thereof.

The reduced end of the crank-shaft from the face of the nearest crank to its end is made tubular, as shown in Fig. 4, with a conical en- This sharp edge deflects any oil flowing or moving across the face of the crank and directs it into the interior of the crank-shaft, from which it works through all the various bearings accessible therefrom, thereby to lubricate the same.

The throttle at F may be operated in any suitable manner and from any desired position, as may also the controlling-valve. The reversing-shaft 0 is provided with an arm 0 to which is secured a suitable operating-lever 0 leading to any desired point convenient for the operator of the engine. The location of the controlling-levers for the controllingvalve, the throttle-valve, and the reversing mechanism may be obviously arranged at any suitable point and operate in any desired manner.

My invention is not limited to the particular embodiment thereof herein shown and described and obviously not to the particular application which is herein made of the same,

the present description and illustration being submitted for illustrative purposes only. From this theinvention may be varied without departing from the spirit and scope thereof.

I claim- 1. A steam-engine provided with a plurality of cylinders, a crank-shaft rotated therefrom, a plurality of eccentrics and valves operated thereby for the respective cylinders, and means to impart dilferential rotative movement to the said eccentrics for reversing the engine.

2. A steam-engine provided with a plurality of cylinders, a crank-shaft rotated therefrom, a plurality of eccentrics and valves operated thereby for the respective cylinders, and means to impart differential rotative movement to the said eccentrics, one by and from the other.

3. A steam-engine having a plurality of cylinders, pistons therein, and a crank-shaft rotated therefrom, a plurality of eccentrics and valves operated thereby for saidcylinders, a rotatable, spirally grooved sleeve on said crank-shaft upon which one of said eccentrics is fixedly, and the other loosely mounted, and means movable longitudinally of the said crank-shaft and engaging said spiral slot to impart partial rotation thereto on and relative to said shaft.

4:. An engine having a plurality of cylinders, pistons therein, a crank-shaft rotated therefrom, a spirally-slotted sleeve rotatably mounted on said crank-shaft, a plurality of eccentrics one fixedly and the other loosely mounted upon said sleeve, means connecting the loosely-mounted eccentric with the fixedlymounted eccentric for moving the former by the latter, and means to engage the spiral slot of said sleeve to rotate the latter and thereby the said eccentric for reversing the engine.

5. An engine having a plurality of cylinders, pistons therein, and a crank-shaft rotated thereby, a plurality of eccentrics rotated by said crank-shaft, and valves operated thereby for the said cylinders, means to shift one of said eccentrics and means connecting the said eccentrics whereby to shift the other eccentric also, said connecting means providing for lost motion between said eccentrics on the shifting of one by the other.

6. An engine having a plurality of cylinders, pistons therein, a crank-shaft rotated thereby, a spirally-slotted sleeve rotatably mounted on said crank-shaft, a plurality of eccentrics one of whichis fixedly and the other movably mounted on said sleeve, means engaging said spiral slot partially to rotate said sleeveand thereby the eccentric fixedly mounted thereon, and means connecting said fixedly-mounted eccentric with the looselymounted eccentric for moving the latter by the former, said connecting means permitting a lost motion between the two on shifting thereof for reversing the engine.

7. An engine having a plurality of cylinders, pistons therein and a crank-shaft operated thereby, a spirally-slotted sleeve rotatably mounted on said crank-shaft, means lon-,

gitudinally movable within said crank-shaft and extending outwardly therefrom through a longitudinal slot therein, to engage said spiral slot, whereby to rotate partially the said sleeve, an eccentric fast on said sleeve, and an eccentric loose thereon, with a studand-slot connection between the two for moving the one by the other and permitting of lost motion between them, and valve mechanism actuated by said eccentrics.

8. An engine having a plurality of cylinlVitn esses:

ELIZABETH HEYwooD, lVIAUD A. HEYwooD. 

